html, body {
            height: 100%;
            margin: 0;
            overflow: hidden;
            background-color: #000;
            touch-action: manipulation;
            -webkit-overflow-scrolling: touch;
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
        }
        #callContainer {
            width: 100%;
            height: 100vh;
            max-width: 400px;
            max-height: 100vh;
            background: linear-gradient(to bottom, #1a1a1a 0%, #4a4a4a 100%);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            padding: 1rem;
            padding-bottom: calc(1rem + env(safe-area-inset-bottom));
            color: white;
            box-sizing: border-box;
            margin: 0 auto;
            border-radius: 1.5rem;
        }
        #callHeader {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }
        #signalIcon {
            font-size: 1.25rem;
        }
        #currentTime {
            font-size: 1rem;
            color: #a1a1aa;
        }
        #callInfo {
            text-align: center;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }
        #callStatus {
            font-size: 1.5rem;
            font-weight: 600;
            color: #a1a1aa;
        }
        #callTimer {
            font-size: 1.25rem;
            color: #a1a1aa;
            margin-top: 0.5rem;
            display: none;
        }
        #keypad {
            display: none;
            grid-template-columns: repeat(3, 1fr);
            gap: 1rem;
            margin-top: 1rem;
            justify-items: center;
        }
        #keypad button {
            background-color: rgba(255, 255, 255, 0.15);
            color: white;
            border-radius: 50%;
            width: 60px;
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: background-color 0.2s;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }
        #keypad button:hover {
            background-color: rgba(255, 255, 255, 0.25);
        }
        #callControls {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            justify-items: center;
            gap: 1rem;
            margin-bottom: 3rem;
            margin-top: 3rem;
            position: sticky;
            bottom: 3rem;
        }
        #callControls button {
            background-color: rgba(255, 255, 255, 0.15);
            color: white;
            border-radius: 50%;
            width: 60px;
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: background-color 0.2s;
            border: 1px solid rgba(255, 255, 255, 0.2);
        }
        #callControls button:hover {
            background-color: rgba(255, 255, 255, 0.25);
        }
        #callControls button.active {
            background-color: #007aff;
            border-color: #007aff;
        }
        #hangupButton {
            background-color: #ff3b30 !important;
            color: white;
            border-radius: 50%;
            width: 60px;
            height: 60px;
            display: none;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            cursor: pointer;
            transition: background-color 0.2s;
            border: 1px solid rgba(255, 255, 255, 0.2);
            z-index: 10;
        }
        #hangupButton.recall {
            background-color: lch(68.88% 94.87 136.92) !important;
        }
        #hangupButton.recall:hover {
            background-color: lch(68.88% 94.87 136.92) !important;
        }
        #hangupButton:hover {
            background-color: #e02424 !important;
        }
        /* PC styles */
        @media (min-width: 768px) {
            #callContainer {
                border-radius: 2rem;
                box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
                max-width: 400px;
                max-height: 600px;
                margin: auto;
            }
            #callControls {
                margin-top: 0;
                margin-bottom: 1rem;
                position: relative;
                bottom: 0;
            }
        }
        /* Mobile styles */
        @media (max-width: 400px) {
            #callContainer {
                padding: 1rem;
                padding-bottom: calc(10rem + env(safe-area-inset-bottom));
            }
            #keypad button {
                width: 50px;
                height: 50px;
                font-size: 1.25rem;
            }
            #callControls button {
                width: 50px;
                height: 50px;
                font-size: 1.25rem;
            }
        }